ESP32-S2
Overview
ESP32-S2 is a highly integrated, low-power, single-core Wi-Fi Microcontroller SoC, designed to be secure and cost-effective, with a high performance and a rich set of IO capabilities. 1
The features include the following:
RSA-3072-based secure boot
AES-XTS-256-based flash encryption
Protected private key and device secrets from software access
Cryptographic accelerators for enhanced performance
Protection against physical fault injection attacks
Various peripherals:
43x programmable GPIOs
14x configurable capacitive touch GPIOs
USB OTG
LCD interface
camera interface
SPI
I2S
UART
ADC
DAC
System requirements
Build Environment Setup
Some variables must be exported into the environment prior to building this port. Find more information at Environment Variables on how to keep this settings saved in you environment.
Note
In case of manual toolchain installation, set ESPRESSIF_TOOLCHAIN_PATH accordingly.
Otherwise, set toolchain path as below. If necessary.
On Linux and macOS:
export ZEPHYR_TOOLCHAIN_VARIANT="espressif"
export ESPRESSIF_TOOLCHAIN_PATH="${HOME}/.espressif/tools/zephyr"
On Windows:
# on CMD:
set ESPRESSIF_TOOLCHAIN_PATH=%USERPROFILE%\.espressif\tools\zephyr
set ZEPHYR_TOOLCHAIN_VARIANT=espressif
# on PowerShell
$env:ESPRESSIF_TOOLCHAIN_PATH="$env:USERPROFILE\.espressif\tools\zephyr"
$env:ZEPHYR_TOOLCHAIN_VARIANT="espressif"
Finally, retrieve required submodules to build this port. This might take a while for the first time:
west espressif update
Note
It is recommended running the command above after west update so that submodules also get updated.
Flashing
The usual flash target will work with the esp32s2_saola board
configuration. Here is an example for the Hello World
application.
# From the root of the zephyr repository
west build -b esp32s2_saola samples/hello_world
west flash
Refer to Building an Application and Run an Application for more details.
It’s impossible to determine which serial port the ESP32-S2 board is
connected to, as it uses a generic RS232-USB converter. The default of
/dev/ttyUSB0 is provided as that’s often the assigned name on a Linux
machine without any other such converters.
The baud rate of 921600bps is recommended. If experiencing issues when flashing, try halving the value a few times (460800, 230400, 115200, etc).
All flashing options are now handled by the West (Zephyr’s meta-tool) tool, including flashing
with custom options such as a different serial port. The west tool supports
specific options for the ESP32-S2 board, as listed here:
- --esp-idf-path ESP_IDF_PATH
path to ESP-IDF
- --esp-device ESP_DEVICE
serial port to flash, default $ESPTOOL_PORT if defined. If not, esptool will loop over available serial ports until it finds ESP32 device to flash.
- --esp-baud-rate ESP_BAUD_RATE
serial baud rate, default 921600
- --esp-flash-size ESP_FLASH_SIZE
flash size, default “detect”
- --esp-flash-freq ESP_FLASH_FREQ
flash frequency, default “40m”
- --esp-flash-mode ESP_FLASH_MODE
flash mode, default “dio”
- --esp-tool ESP_TOOL
if given, complete path to espidf. default is to search for it in [ESP_IDF_PATH]/components/esptool_py/ esptool/esptool.py
- --esp-flash-bootloader ESP_FLASH_BOOTLOADER
Bootloader image to flash
- --esp-flash-partition_table ESP_FLASH_PARTITION_TABLE
Partition table to flash
For example, to flash to /dev/ttyUSB2, use the following command after
having build the application in the build directory:
west flash -d build/ --skip-rebuild --esp-device /dev/ttyUSB2